1. Field of the Invention
The present invention relates to a system for providing either base lubrication, or additional oil to an internal combustion engine camshaft for the purpose of either lubricating the camshaft, or for controlling a device such as a camshaft timing phaser or camshaft profile switching mechanism.
2. Disclosure Information
The camshafts of reciprocating internal combustion engines are usually lubricated by means of oil brought up either through the cylinder block of the engine, as is the case of cam-in-block configurations, or with oil brought up through a cylinder head and then through the towers upon which the camshaft is mounted. The latter system generally works well, but presents an issue in the event that it is desired to build engines having non-adjustable valve timing, as well as engines having camshaft phasing, from a common supply of cylinder heads. A problem arises because if camshaft phasing is desired, it is usually necessary to provide an oil pressure signal to the camshaft phaser. This necessitates a provision such as a valve port and additional plumbing in the cylinder head to facilitate such an oil pressure signal. Unfortunately, it is an unnecessary expense to provide the basis for such valving in every engine built in a range, when only a fraction of the engines will be equipped with camshaft phasing.
The present invention allows the use of camshaft phasing with a common cylinder head having little if any additional cost built in to accommodate camshaft phasing, which in turn reduces the cost burden on engines which are not equipped with camshaft phasing.